A traditional low cost positioning method for an unmanned aerial vehicle (UAV) in a small area is typically based on color cards.
At present, the color cards in the traditional positioning method have as many as 10 to 20 colors. However, these colors of the color cards are difficult for the UAV to distinguish, such as the colors light yellow and beige. Therefore, the recognition error rate is relatively high during the positioning process.
In another positioning method, tetragonal color cards are used in the positioning method. However, this positioning method is unable to effectively identify a rotation angle and the position of a rotating UAV.